In nature, a variety of solute-bearing materials can be found in which the solute in the material can be utilized in a variety of ways. For example, plant materials can contain a variety of oil type compositions that can be used as edible oils or as fuels. Likewise, oil sands contain petroleum type oils that can be recovered and ultimately used as feedstocks for the production of fuels or lubricants.
The extraction of solute from solute-bearing material can be carried out in a variety of ways. In some cases, the solute is extracted by pressing. In others, the solute is extracted using an appropriate solvent.
U.S. Pat. No. 5,707,673 discloses a solvent extraction type process in which a mixture of a solvent is used to extract an extractive from extractive-containing material in an extraction zone. A miscella comprising a portion of the process solvent and a portion of the extractive, and an extractive-depleted substrate is formed, and the miscella is removed from the extraction zone. The removed miscella is filtered by use of a microfiltration, an ultrafiltration, a nanofiltration, or a reverse osmosis membrane to separate the solvent in the miscella from the extractive in the miscella, and at least a portion of the separated solvent is recycled to the extraction zone.
U.S. Pat. No. 7,384,557 discloses a process for separating a solute from a solute-bearing product. The solute-bearing solid product is fed to an extraction chamber equipped with an auger adapted to promote a free-floating flow of product. A solvent is injected into the extraction chamber through at least one spray nozzle extending so as inject the solvent in a vortex-shaped solvent spray pattern to contact the flow of product. A mixture of the leached solute and solvent is collected from the extraction chamber, and the leached solute is separated from the solvent.
More efficient processes are sought to extract solute from solute-bearing materials. It is particularly desirable to obtain processes that are highly efficient in extracting oils that can be used as edible materials or that can be used as feedstocks for the production of fuels or lubricants.